|x - 4| + |x + 11| - 48 = |-7 - 4| + |-7 + 11| - 48 = |-11| + |4| - 48 = 11 + 4 - 48 = 15 - 48 = -33
3x - (x + 4) = 3 ⋅ 7 - (7 + 4) = 21 - 11 = 10
Ответ: 2. а) -33; б) 10